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linux/scripts/mod/modpost.h
Denys Vlasenko 1ce53adf13 modpost: support objects with more than 64k sections
This patch makes modpost able to process object files with more than
64k sections. Needed for huge kernel builds (allyesconfig, for example)
with -ffunction-sections. 64k sections handling is covered, for example,
by this document:

"IA-64 gABI Proposal 74: Section Indexes"
http://www.codesourcery.com/public/cxx-abi/abi/prop-74-sindex.html

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-03 15:05:56 +02:00

198 lines
5.1 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <elf.h>
#include "elfconfig.h"
#if KERNEL_ELFCLASS == ELFCLASS32
#define Elf_Ehdr Elf32_Ehdr
#define Elf_Shdr Elf32_Shdr
#define Elf_Sym Elf32_Sym
#define Elf_Addr Elf32_Addr
#define Elf_Sword Elf64_Sword
#define Elf_Section Elf32_Half
#define ELF_ST_BIND ELF32_ST_BIND
#define ELF_ST_TYPE ELF32_ST_TYPE
#define Elf_Rel Elf32_Rel
#define Elf_Rela Elf32_Rela
#define ELF_R_SYM ELF32_R_SYM
#define ELF_R_TYPE ELF32_R_TYPE
#else
#define Elf_Ehdr Elf64_Ehdr
#define Elf_Shdr Elf64_Shdr
#define Elf_Sym Elf64_Sym
#define Elf_Addr Elf64_Addr
#define Elf_Sword Elf64_Sxword
#define Elf_Section Elf64_Half
#define ELF_ST_BIND ELF64_ST_BIND
#define ELF_ST_TYPE ELF64_ST_TYPE
#define Elf_Rel Elf64_Rel
#define Elf_Rela Elf64_Rela
#define ELF_R_SYM ELF64_R_SYM
#define ELF_R_TYPE ELF64_R_TYPE
#endif
/* The 64-bit MIPS ELF ABI uses an unusual reloc format. */
typedef struct
{
Elf32_Word r_sym; /* Symbol index */
unsigned char r_ssym; /* Special symbol for 2nd relocation */
unsigned char r_type3; /* 3rd relocation type */
unsigned char r_type2; /* 2nd relocation type */
unsigned char r_type1; /* 1st relocation type */
} _Elf64_Mips_R_Info;
typedef union
{
Elf64_Xword r_info_number;
_Elf64_Mips_R_Info r_info_fields;
} _Elf64_Mips_R_Info_union;
#define ELF64_MIPS_R_SYM(i) \
((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
#define ELF64_MIPS_R_TYPE(i) \
((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1)
#if KERNEL_ELFDATA != HOST_ELFDATA
static inline void __endian(const void *src, void *dest, unsigned int size)
{
unsigned int i;
for (i = 0; i < size; i++)
((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1];
}
#define TO_NATIVE(x) \
({ \
typeof(x) __x; \
__endian(&(x), &(__x), sizeof(__x)); \
__x; \
})
#else /* endianness matches */
#define TO_NATIVE(x) (x)
#endif
#define NOFAIL(ptr) do_nofail((ptr), #ptr)
void *do_nofail(void *ptr, const char *expr);
struct buffer {
char *p;
int pos;
int size;
};
void __attribute__((format(printf, 2, 3)))
buf_printf(struct buffer *buf, const char *fmt, ...);
void
buf_write(struct buffer *buf, const char *s, int len);
struct module {
struct module *next;
const char *name;
int gpl_compatible;
struct symbol *unres;
int seen;
int skip;
int has_init;
int has_cleanup;
struct buffer dev_table_buf;
char srcversion[25];
};
struct elf_info {
unsigned long size;
Elf_Ehdr *hdr;
Elf_Shdr *sechdrs;
Elf_Sym *symtab_start;
Elf_Sym *symtab_stop;
Elf_Section export_sec;
Elf_Section export_unused_sec;
Elf_Section export_gpl_sec;
Elf_Section export_unused_gpl_sec;
Elf_Section export_gpl_future_sec;
const char *strtab;
char *modinfo;
unsigned int modinfo_len;
/* support for 32bit section numbers */
unsigned int num_sections; /* max_secindex + 1 */
unsigned int secindex_strings;
/* if Nth symbol table entry has .st_shndx = SHN_XINDEX,
* take shndx from symtab_shndx_start[N] instead */
Elf32_Word *symtab_shndx_start;
Elf32_Word *symtab_shndx_stop;
};
static inline int is_shndx_special(unsigned int i)
{
return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
}
/* shndx is in [0..SHN_LORESERVE) U (SHN_HIRESERVE, 0xfffffff], thus:
* shndx == 0 <=> sechdrs[0]
* ......
* shndx == SHN_LORESERVE-1 <=> sechdrs[SHN_LORESERVE-1]
* shndx == SHN_HIRESERVE+1 <=> sechdrs[SHN_LORESERVE]
* shndx == SHN_HIRESERVE+2 <=> sechdrs[SHN_LORESERVE+1]
* ......
* fyi: sym->st_shndx is uint16, SHN_LORESERVE = ff00, SHN_HIRESERVE = ffff,
* so basically we map 0000..feff -> 0000..feff
* ff00..ffff -> (you are a bad boy, dont do it)
* 10000..xxxx -> ff00..(xxxx-0x100)
*/
static inline unsigned int shndx2secindex(unsigned int i)
{
if (i <= SHN_HIRESERVE)
return i;
return i - (SHN_HIRESERVE + 1 - SHN_LORESERVE);
}
/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
static inline unsigned int get_secindex(const struct elf_info *info,
const Elf_Sym *sym)
{
if (sym->st_shndx != SHN_XINDEX)
return sym->st_shndx;
return shndx2secindex(info->symtab_shndx_start[sym -
info->symtab_start]);
}
/* file2alias.c */
extern unsigned int cross_build;
void handle_moddevtable(struct module *mod, struct elf_info *info,
Elf_Sym *sym, const char *symname);
void add_moddevtable(struct buffer *buf, struct module *mod);
/* sumversion.c */
void maybe_frob_rcs_version(const char *modfilename,
char *version,
void *modinfo,
unsigned long modinfo_offset);
void get_src_version(const char *modname, char sum[], unsigned sumlen);
/* from modpost.c */
void *grab_file(const char *filename, unsigned long *size);
char* get_next_line(unsigned long *pos, void *file, unsigned long size);
void release_file(void *file, unsigned long size);
void fatal(const char *fmt, ...);
void warn(const char *fmt, ...);
void merror(const char *fmt, ...);